Consider the following statements for fluidized bed boilers:

1. Fluidized bed boilers produce steam from fossil and waste fuels by using a technique called fluidized bed combustion.

2. Cyclone separators are gas cleaning devices that utilize the centrifugal force created by a spinning gas stream to separate particles from a gas.

3. In a pressurized fluidized bed boiler, the combustion process takes place in a pressurized environment resulting in a compact furnace and improved combustion efficiency.

Which of the above statements are correct?